Parking brake assembly



July 5, 1960 Filed Nov. 25, 1955 T. H. JoHNsToNE v 2,943,511

PARxmG` BRAKE ASSEMBLY 3 Sheets-Sheet 1 LFE 1122:? T

Theodore H rfuzszozze 1'. H. JoHNsToNE PARKING Bamm ASSEMBLY July 5,1960 v 3 Sheets-Sheet 2 Filed Nov. 425, 1955 C: mi

July 5, 1960 T. H. JoHNsToNE 2,943,51

PARKING BRAKE ASSEMBLY Y Filed Nov. 25, 1955 s sheets-sheet s UnitedlStates Patent PARKING BRAKE ASSEMBLY Theodore H. Johnstone, Detroit,Mich., assignor, by mesne assignments,v to The Bingham-HerbrandCorporation, a corporation of Ohio v Y Filed Nov. 25, 1955, Ser. No.549,054

8 Claims. (Cl. 74529) This invention relates to a brake lever assembly,and particularly `to such an assembly which is adapted to combined useas an emergency and parking brake for a vehicle.

It is an important object of the present invention to provide a noveland improved foot operated brake lever assembly.

It is a further important object of lthe present invention to provide ayfoot operated brake lever assembly having means for retaining the brakelever in a 4brake setting condition, and wherein the brakeleveriretaining means is normally inactive thereby facilitating Vthe useof the brake lever assembly asan emergency brake.

It iswanother object of the present invention to provide a novel handcontrolled release mechanism for a foot operated brake lever assembly.

Yet another object of the present invention is to pro;

vide'a footioperated brake lever assembly utlizing'a hand orl footrelease control requiring a minimum of operating space.

In accord-ance with one of the embodiments 'of the present invention,there is provided a footopera-ted brake lever assembly having ratchetsector and pawl means for retaining the brakes in an attained brakesetting condition, andhaving a handV operated rod biased to a convdition maintaining the pawl Aand ratchet sector out of engagement, butbeing capableof retention in a second position requiring engagementbetween the pawl and ratchet means lduring operation of Ithe assembly asa parking brake.

It is a further object of the present invention to provide a footoperated parking brake assembly having a release mechanism which can bereleased with relatively little eiort by the operator. e

In accordance with afurther embodiment of the present invention theresprovided Ia foot operated brake lever assembly wherein ratchet and pawlmeans are nor-V mally in disengaged relation so that the'brake leverassembly may be used as an emergency brake but where a push but-ton maybe depressed to place the ratchet and pawl means in engageablerelation,frictional forces between 4the ratchet and pawl means being relied uponto maintain the engagedv relation after release ofthe push button, and''the brakes -being released byv Vpressing "on the ioot7"pedal`"of-thebrakelever assembly.

Another object of the present invention isto provide a novel ratchetfandpawl means lfor a foot operated brake lever. "f `Y Otherobjects,-features and advantages of the present invention will beapparent' from the following` detailed description taken in connection-with'the accompanying drawings, in which:

On the drawings:

Figure lis aj'fragmentary'side elevational view and illustrates 7a rstform of foot'operated brake lever assembly 4in laccordance with thepresentl invention;

f Figure 2 lis a iragnientary'rtop plan view of the struc,

ture-'cf Figure 1;-

Patented July 5, 1960 Figure 3 is a fragmentary side elevational view ofae portion of v.the structure of Figure 1 but illustrating the ratchetand pawl means in normal disengaged relation;Y

Figure 4 is a cross sectional view taken generally along the line oflV-IV of Figure l; v

Figure 5 is a fragmentary side elevational view of a second embodimentof brake lever assembly in accordance with the present invention withcertain parts broken away and in section, and

Figure 6 is a`fragmentary side elevational View similar to Figure 5but'illustrating :the ratchet and pawl means in engageable relation forYoperation as a'parking brake.

As shown on the drawings:

Referring to Figures 1 through 4, it will be observed that the brakelever assembly therein illustrated corni prises a foot operated leverarm 10 `which is pivotally mounted by means of a rivet 111to a bracket1'2 and is connected at its upper end to a link 14 secured to brakeactuating cable 15. The cable housing 16 may be clamped to the bracket12 by means of a mechanism indicated at 17. Thus, as foot pedal 19is'depressed, the brake cable 15 is retracted to transmit a vbrakesetting force.

When the assembly is to be used as a parking brake, it is of courserequired that the brakes ybe retained in the desired brake settingcondition after the operator has released the foot pedal 19. To thisend, ratchet and pawl means are provided for retaining the lever arrn`10in successive incremental brake setting positions, this re taining meansincluding a ratchet sector 22.l pivotally con# nected at 23 to thebracket 12 and coupled to the brake lever Varm l() by means of a pin 24extending through a circular aperture in the side walls such as 10a ofthe brake lever arm 10 and through an elongated slot 25 extendingradially of the pivot Z3 in the ratchet sector 22.Y Thus, as the brak-elever 10 is pivoted 'about the rivet 11, the ratchet sector 22 is causedto move therewith arcuately about the pivot 23 while the pin 24 travelsin the slot 25 to accommodate lthe relative movement between lthe brakelever and the ratchet sector radially of the pivot 23.

Cooperating with the ratchet sector in maintaining the brake lever inattained brake setting positions is a pawl member 30 pivotally mountedat 31 to the bracketV 12 and having a tooth 32 of configuration tocooperate with the ratchet teeth 22a on the ratchet sector 22. The pawl3i) has a right angle flange 33 which provides a means for attachment tothe hand operated release mechanism to be hereinafter described fornor-mally maintainf ing the pawl tooth 32 out of engageable relationl tothe ratchet teeth 22a and for moving the tooth into engageable relationto the ratchet teeth as shown in Figure l when it is desired to operatethe assembly as a parking brake.

The hand release mechanism for controlling the` pawl 30 comprises anelongated rod 40 which may be mounted by means of a bracket 41r to theinstrument panel or related Vstructure of a motor vehicle. Thebracketprovides walls 41a and 41b having circular apertures for lguiding axialand rotary movement of the rod 40. At its forward end the rod is coupledto the flange 3,, as illustrated in Figure 2 by extending through anaperture therein and having a suitable pin means 43 preventing rearwardmovement of the rod 40 relative to the flange 33. For urging theflange33 to move with the rod 40 in the forward direction, a collar 45is locked to the rod 40 by means of a suitable ring 46 and a compressionspring 48 is disposed between the washer 45 and the ange 33. Springmeans lill'isA bottomed against the wall 41a and acts on a collar 49secured against rearward move,

ment on the rod 40 to urge` the rod 40 into a rearward position. Toretain the rod' 40 in a forward position against the action of thespring 60, the bracket 41 provides @further flange portion 41C having apair of radial slotsA 6J, extending fromA aV central: aperture 6,2closely receiving the rodi 40, and the rod'40' has a pair of radialsplines 5`1 april' SZ for extension in these radial' slotsA of the ange41e;

InV Operation f the embodiment of Figures l t0 4, ttrset4 the. brakes,the rod 40' isv moved` forwardly until the rear ends of. thespli'nes 51anlLEZY clear the wall 41C, after which the handle 54' is twisted to.move the splines :1 a nl5 2A out of alignment withthe correspondinglradial slots inthe, wall 41'c, For example, the handle may be turned`through.Y 9,()` degrees from, the. vertical position shown in Figure 1`to a horizontal position to lock the rod 40 in its forward positiom. inwhich position the spring`48 actsto urge thepawl tooth,32, intoengageable relation. to. the ratchetteethpZZa. Toreleasethe brakes,thehandle- 54 isA turnedrback` to its normal orientation whereupon,`spring 60I will' retract the pawl 30 to nonratcheting. position shown inFigure 3. In the release position offVA-'the assembly thesplines 5'1Land 52 extend thrgughthe correspondingradialislots in the wall portion41 c.a.iid the,spring60 is in-extendedcondition as shown In Figures 5and 6, there is illustrated a similanbrake IGYGIP: bracket. assembly,and.. the same. reference numeralshaye been,applied tothe correspondingparts inrFiguresl, and 5. However, in Figure 5, the manualreleasemechanismffor positioning the. pawl 30.- comprises aflpiush.buttonv80 carried by` the instrument panel 81 of the vehicle.` Thepushbutton is reciprocable in a tubular housingz` and-is connectedwith amember 83 slidable irrthe housingBZ, by means of an .enlarged diameterend p0 rt ion.84.. Theend portion S4 receives afcompression spring, 8,5Abottomed atits. forward end against the housingz. Themember S3 is alsocoupled to. a member 857-` having a.anged end 8S fitting Within theenlarged diametenportion 84 of the rst member- 83 and coupled to.a=,rod90 by means of a p in. 91 to transmit motion attire;y button 80 tothefpawl, 30 throughring., 91', collar 9.2:,andcompression; spring 93..The, spring, 93` abuts against1 at .right angle. ange' 33. whichcorresponds` to. theA ange 33 of Figure 2. Thus, when therbutton 8) ispressedi;springg93rurgesgthepawl 30 into ratchetingposition,- and` when.the .bntton.80. is released the springV 85 returnsthe button 80 tonormal. position.- Pin means 43 couplesftherod. 90v to the pawl 30 inthe. rearward direction, so -that spring 85-wi1l normally causethe pawl30 tofassumef anon-ratcheting position.

Inoperationl of the assembly of Figures 5 and 6, the pawlgisnormally outof, ratcheting position as illustrated in: Figure15, so-that if thebr-aln=, peda1 19 is depressed and. released, the brakes; areapplied andthenreleased. To operate. the assembly asa parking brake, theped'al'i 19may be -moved forwardly andthereafter the button 80 depressed to movethe pawl 30 into ratcheting position shown' inv Figure 6 and the footpedal released witliY the button` depressed; var-alternatively, the.button 80 may be iirst depressed, the foot' pedal 19 thereafter mol/@dioshift th'eratchet'sector 22'pr0gressively past the pawl' 32, andthebrake pedal then released to allow th'egpawl tooth :to moveinto. tightengagement with. one ofthe, ratclet,teeh. After release ofthe footpedal, the buttonlbmay be releasedsnce. the friction bctweeirtheratchetfandpawlcaused, by. theftension of` the.brakes. will pigmentdisengagemennthereof byspring 85. Under these cirurnstancesigtoreleasethe.. brakes, itis only/,necessary tqgapply', slight pressureto the footpedal 1.9,.. relieving htgfrqtionbetyveenithe ratchet sector andrpawl,and; allqwingthefsprng to snap.. the pawl: toothv out ofengggmeptf,witlythefratchetsector-5;. Whereupon;,the, lever 10 willreturn to its initial brake release condition under control of the footof theoperator;

Figures 3 and 6 illustrate a modied ratchet tooth and pawl constructionwherein the engagement faces such as a of ratchet teeth 109 and 101a ofpawl tooth 101 extend at relatively steep angles relative to a radialplane through the pivot 23 ion theI ratchet sector. In this manner, the,teeth 100., and. 101 are positively interlocked when foot pressure isrelcase'd from the' foot pedal 19, and the fulk tensionr of.tbesbrakezisallowed to be' exerted between the ratche andi pawl teeth.100: and 1ML. However, the teeth 10i) and 1012 arereleased'by'slightpressure in the forward.- directionv on'v the brakepedalA as in the embodiments of Figures 1 and 5.

There is thus Vprovided in accordance" with the present invention abrake applying means having a retaining means for retaining the applyingmeans in an attained brake applyingiposition, wherein the retainingmeans is normallyroutroh retainingrelationlto'the brake applying meanssothat iftheapplyingmeans is actuated by the operator in a suddenemergency, the brakes will automatically releasewhenthe operatorreleases the applying means. In prior. art parking brakes, the retainingmeans is normally in retaining relation to the brake applying meansandrequiresa separate movement bythe operator to. release.A Under, theseprior artY circumstances,y if the parking brake is applied"U during asudden emergency, the.v operator. tends notto thinker' the separaterelease operation. withrthe resultthatthe brakes are locked inactuatedconditionandQtheyehicle is thrown into. a skid. Thepresent',inventi'cnl` prevents` this panic lock ofthe brakes andrepresentsan importantA advance in this art. The present invention,vreadilyA -applied`to straight pull brake lever assembliesand'fotherparking brake structures for preventingfpaniclock`thereot as will'beunderstood by those skilled.' in the art from a study of the specificillustrative embodiments herein described.v

Itfwillbetapparent that many modifications and variations.` maybeeiected without departing from the scope ofthe novel concepts ,of 'thepresent invention.

l claim as my inventions.

1. A lever structure comprisingrbracketmeans, a lever arm. pivotallymounted by said.v bracket means 'for swingingr movement.. to. apply,an.. actuating, force, ratchet and pawl means operably connected.betweennsaid lever arm and said;bracket,means forretainingsaid leverarm in an actuating position to which it is moved whenthe ratchet andypawl means .for saidratchet .andpawl means are. in. engagealalerelatiom; control. meansin one position maintaining, said ratchetandpawl meansinsaidLengageabIe relation and in a secondposition.maintainingsaid ratchet and-pawl means: out. of. engageablevrelation, resilient means arranged to normally maintainfsaid controlmeans in said second`r position, a. memberconnectedto. said .controlymeans,- for: moving; the, same. to. said. rst position to causefsaidleven armto` be retained in force applying position. to. which..moved',.. and. means `for: retaining., said control means-in.saidrstfpositiom. said.,retaining means being releasableby manipulationof: saidmembergsaid retainingmeanscomprisingselfflocking teeth.of saidratchet and pawl. means iwhich.. maintain. said control. means in saidrst position. by friction resulting :from the tension on the-lever arm.'

A brake lever:;structure comprising -bracket means for mounting in avehicle, a lever arm pivotally mounted by said bracket means for.swinging movement'to apply a brake settingyforce, .a ratchet sectorpivotally'mounted by saidbracket means/and swingable. Withsaid leverarm, pawl means pivotally mounted by saidbracket; means for movementbetween a first position in engageable relation with the. ratchetsectonanda second .positionout of engageablev relationzwith.saidratchetsector,a control. rod reciprocally. mounted-.by said.bracketmeansandoperablyconnected to said pawl means-for.. .moving .betweemrst and secondpositions to move said pawl means.A between j its first" and secondpositions, rspring means arranged to normally maintain said rod towardits second position to hold said pawl means out of engageable relationto saidratchet sector, and abutment means carried by said rod andengageable with said bracket means by axial shifting of the rod from itssecond to its rst position and slight rotation of the rod to retain therod in its first position with the ratchet sector and pawl means inengageable relation.

l3. A brake lever structure comprising bracket means for mountingin avehicle, a lever arm pivotally mounted by said bracket means forswinging movement to apply a brake setting force, a ratchet vsectorpivotally mounted by said bracket means and swingable with said leverarm, pawl means pivotally mounted by said bracket means for movementbetween a rst position in engageable relation with. theratchetV sectorand a second position out of engageable'relation with said ratchetsector, a control rod reciprocally mounted by said bracket means andoperably connected to said pawl means for moving between tirst andsecond positions to move said pawl means between its first and secondpositions, and resilient means arranged to normally maintain said rod inits second position to hold said pawl means out of engageable relationto said ratchet sector, said ratchet sector having a series of ratchetteeth and said pawl means having a tooth for engagement with successiveones of said lratchet teeth, the engaging faces of said teeth extendingat a substantial angle to a radial plane to provide self-locking betweenthe ratchet teeth and pawl means to lock said lever arm in a brakesetting position.

4. A foot operated brake lever structure comprising bracket means formounting in a vehicle, a. lever arm pivotally mounted by said bracketmeans for swinging movement to apply a brake setting force to the brakesof the vehicle, a ratchet sector having arcuately disposed ratchet teethpivotally mounted by said bracket means and connected with said leverarm for pivotal movement therewith, a pawl member pivotally connected tosaid bracket means and depending therefrom adjacent said ratchet teethand having a tooth projecting therefrom for movement into engageablerelation Ito the ratchet sector teeth for retaining the brake lever insuccessive angular positions to which moved inthe brake settingdirection, a reciprocal actuating rmonnected to said pawl member, arigid connection between said rod and said pawl member for requiringmovement of said pawl member from a tirst position with the tooth -inengageable relation to the ratchet teeth to a second position with thetooth out of engageable relation to the ratchet teeth, a resilientconnection between said rod and said pawl member for urging said pawlmember toward said rst position as said rod is moved toward said ratchetsector, spring means connected to said bracket means and to said rod andin a state of compression torurge said rod away from said ratchet'sector to move said pawl member to second position with the pawl toothout of engageable relation to the ratchet teeth, and interengagementmeans carried by said rod and said bracket means for engagement uponmovement of the rod toward said ratchet member and slight rotation ofsaid rod. l

5. A foot operated brake lever structure comprismg l bracket means formounting in a vehicle, alever arm pawl member, a rod for rigidconnection with said pawl member in moving said pawl member from irst tosecond position, and for resiliently urging the pawl member from secondposition to first position in a iirst position of the rod, push buttonmeans coupled to said rod for depression to move said rod to its irstposition to urge said pawl member toward its first position, and springmeans connected to said push button for urging the push button towardprojected position and for urging said rod toward a second position withsaid pawl member in its second position, the brake tension creating afriction between the pawl tooth and the ratchet tooth with which thepawl tooth is engaged to retain the'button in depressed condition whenthe brake lever is moved to a brake setting position and released, theratchetand pawl teethbeing releasable by exerting a slight pressure onVthe lever arm in the brake setting direction to allow said springymeans to return said rodand pawl member to their second positions.

6. A foot operated brake lever structure comprising bracket means formounting in a vehicle, a lever arm pivotally mounted by said bracketmeans for swinging movement to apply a brake setting force to the brakesof the vehicle, a ratchet sector pivotally mounted by said bracket meansand connected to said brake lever arm for swinging movement therewith, apawl member pivotally mounted to said bracket means and dependingtherefrom and having a tooth disposed for engagement with successiveteeth of said ratchet member in a first position of said pawl member andfor disposition out of engageable relation to said teeth in a secondposition of said pawl member, a rod for rigid connection with said pawlmember in moving said pawl member from rst to second position,- and forresiliently urging the pawl member from second position to rst positionin a rst position of the rod, manually operable means coupled to saidrod for depression to move said rod to its rst position to'urge saidpawl member toward its first position, and spring means connected tosaid manually operable means for urging the said means toward projectedposition and for urging said rod toward a second position With said pawlmember in its second position, the brake tension creating a frictionbetween 'the pawl tooth and the ratchet tooth with which the pawl toothis engaged to retain the manually operable means in depressed conditionand released, the ratchet and pawl teeth being releasable by exerting aslight pressure on the lever arm in the brake setting direction to allowsaid spring means to return said rod and pawl member to their secondpositions, said ratchet and .pawl teeth having engagement facesextending at a steep angle relative to a radial plane to interlock theteeth by means of the pressure exerted therebetween by the braketension.

7. A foot operated brake lever structure comprising bracket means formounting in a vehicle, a lever arm pivotallymounted by said bracketmeans for swinging movement to apply a brake setting force to the brakesof the vehicle, a ratchet sector having yarcuately disposed ratchetteeth and pivotally mounted by said bracket means and connected withsaid lever arm for pivotal Vmovement therewith, la p-awl memberpivotally connected to said bracket means adjacent said ratchet teethand having a tooth projecting'therefromV for movement into engageablerelation to the ratchet sector teeth for retaining the brake lever insuccessive angular positions to which moved in the brake settingdirection, a reciprocable actuating rod connection to said pawl member,a rigid connection between said rod and said -pawl member for requiringmovement of said pawl member from a rst position with the tooth inengageable relation to the ratchet teeth to a second position with thetooth out of engageable relation to the ratchet teeth, a resilientconnection between said rod and said pawl member for urging said pawlmembervtoward Said rst position when 7 thev rod is in paw! engagingposition, and interengagef ment means: carried by the rodv 4and the`bracket means for` retaining. the rod inV one of its positions:

8. A brakev lever structure comprising bracket means formounting; in4 a5vehicle, a foot-operated` lever atm pivotallyA mounted by' said bracketmeans for swinging movement'toapply aA brakesettingforce,retaining-means mounted for movement with said levers-rmiv cooperatingretaining-means carried by saidf bracket means; said retaining meansbeing operable" in'l a1 first condition` thereof to' retainAsaidleverarfrniiiA attained? brake setting` position' andS b'ein'grelatively movble to a'- second condition to' release' sidi leverarrr'i; a;V controlV member! connected to said retaining meansjforrelativelylv moving th'e retain ing neans' betweenl sid` rst and'sec'o'nd conditions; and depressible buttori-mean's operativelyconnected to said cont'ol renbei 'fo1"act`1'ting` the s'are.'

2,239,916l 2,308,898 2,309,454 2,315,962 2,472,442l 2,531,130 2,-587L7252,591,495 2,694,945 2,835,140

UNiTD STATES PATENTS

